﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo02
{
    class Square:Shape 
    {
        public int sideLen;
        public override void GetArea()
        {
            Console.WriteLine("正方形的面积为："+ sideLen* sideLen);
        }
    }
}
